All vulnerabilities
CVE-2026-55246GHSA-22pc-xxw4-q849

bincookie: Heap buffer overflow via unvalidated `num_pages` when parsing a `.binarycookies` file

Tatsh bincookie
CVSS
7.8High
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 15 Oct 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.22%Chance of exploitation activity in the next 30 days, higher than 12% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in0.1.9Fixed versionGitHub
Published15 Oct 2026Updated 15 Oct 2026CVE List

What fixes it

  • 0.1.9bincookie, c library headerGitHub

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

bincookie is a header-only binarycookies parser. Prior to 0.1.9, bincookie_init_file() in bincookie.h allocates a buffer using the actual .binarycookies file length but trusts the file-controlled num_pages field as the loop bound for byte-swapping page_sizes entries. A crafted file can make the loop read and write beyond the heap allocation, and related unvalidated page sizes and cookie_offsets can drive additional out-of-bounds accesses in page and cookie iteration. Applications that parse an attacker-supplied binarycookies file may crash or suffer heap corruption that can potentially enable code execution. This issue is fixed in version 0.1.9.

Text from CVE List

Affected versions 2

  • bincookieaffected: < 0.1.9CVE List
  • bincookie, c library header<= 0.1.8GitHub

References 3